Magnetic welding ground clamp



March 25, 1958 G. J. WONDRISIKA 2,828,472

MAGNETIC WELDING GROUND CLAMP Filed Feb. 14 ,1957

2 Sheets-Sheet 1 MAGNETIC CIILJ w A05 Arm/(win March 25, 1958 WONDRISKA 2,828,472

MAGNETIC WELDING GROUND CLAMP Filed Feb. 14 ,1957 2 Sheets-Sheet 2 I I I 51:31

INVENTOR. BY 450,665 1/ ///0A/D//.S'KA

United States 2,828,472 MAGNETIC WELDING GROUND CLAMP This invention relates to new and useful improvements in a magnetic welding ground clamp and has for its principal object the provision in a device of this character of a safe, simple and positive magnetic ground for welding equipment.

Another object of my invention is in the provision 1n a device of this character of a permanent magnetized body for establishing an effective ground for welding equipment.

Another object of my invention is in the provision in a device of this character whereby electric current to be grounded is prevented from passing directly through the magnetized clamp.

Still another object of my invention is in the provision in a device of this character of a means for adjusting a ground plate with respect to the magnetized body.

Yet another and equally important object of my invention is in the provision in a device of this character of a removable connection between an electric ground conductor and the adjustable ground plate.

Other objects will appear hereinafter.

The invention consists in the novel combination and arrangement of parts to be hereinafter described and claimed.

The invention will be best understood by reference to the accompanying drawings showing the preferred form of construction, and in which:

Fig. 1 is a perspective view of my clamp on a cylindrically formed ground;

Fig. 2 is an exploded view of the netic clamp;

Fig. 3 is a perspective view of a modified form of my magnetic ground clamp on a cylindrically formed ground;

Fig. 4 is an exploded view of the modified ground clamp.

Referring to Fig. 1, I illustrate a permanent magnetic block 10. This block has its base notched out as at 11 so as to readily accommodate a tubular or cylindrical ground pipe 12.

The top of the block 10 adjacent one side thereof is provided with a rise 13. This rise 13 is recessed as at 14 and this recess 14 is provided with a pair of threaded apertures 15. Adapted to sit in the recess 14 is an insulator 16. This insulator 16 may be of any suitable insulation and of any form or shape to accomplish its desired purpose. I have shown such insulator 16 as having side portions that will extend up and cover the sides of the rise 13, this for a purpose hereinafter made apparent. An arm 17 is fitted to sit on the insulator 16 in the recess 14 of the rise 13 as shown in Fig. 1. This arm 17 is attached to the block 10 by means of screws 18 or the like. Between the screw head and the arm 17 are disposed insulating washers 19. At its free end, which extends laterally from one side of the block 10, the arm 17 provides a circular bearing 20.

Rotatably journaled in the bearing 20 is a hollow internally threaded sleeve member 21. The lower end of parts of my maggroove 24 is exposed beneath the bearing 20 when the member 21 is placed thereon. A split ring spring 25 is clamped in the groove 24 beneath the bearing 20. As the spring 25 is wider than the depth of the groove 24, it will provide a retaining ring below the'bearing 20 and as such the member 21 is rotatably connected to the circular bearing 20.

A hollow ground terminal 26 is provided with an internally and externally threaded extension 27, which extension is adapted to be threaded into the member 21 in a vertical plane as shown in Figs. 1 and 2.

The terminal 26 has a bore 28 formed in one side thereof and which has communication with the interior of the hollow terminal 26. Through this bore 28 is adapted to be inserted a cleaned wire end 29 of the in sulated conductor 30. i

A screw 31 is threadably inserted into the extension 27 of the terminal 26 and by threaded engagement with the internal threads thereof may be brought into holding engagement with the end 29 of the conductor 30 within the hollow terminal 26. Under such a construction the conductor 30 is positively connected to the terminal 26.

Onto the base of the terminal 26 is adapted to be threaded a disc-shaped contact plate 32. When this plate 32 is threaded onto the terminal 26, it will engage the end 29 of the conductor 30. This contact plate 32 is preferably formed of copper or copper alloy which permits an improved electric contact and as such the ground remains cooler thus increasing the efliciency of the welding operation.

In Figs. 3 and 4, I have shown the modified form of construction of my magnetic ground clamp. Such form includes a magnetic block having its base notched at 111. The top of the block 110 is provided with a rise 113 which is recessed as same function as that shown in Figs. 1 and 2. The modification extends to the sleeve member 121 and its associate parts and means of connection to the hearing 120.

The lower end 122 of the member 121 is provided with two spaced apart grooves 123 and 124. grooves 123 and 124 are spaced apart a distance slightly greater than the thickness of the bearing 120. When end 122 is journaled in the bearing split ring springs 125 and 125' are clamped in their respective grooves 123 and 124. Thus the sleeve member 121 is rotatably fastened to the bearing 120.

An elongated terminal 126 is provided with a circular base 126'. The threaded vertical extension 127 is provided by such elongated terminal 126, which is adapted to be threaded in the sleeve 121 when it is rotatably connected to the bearing 120.

A cap 123 having depending lugs 129 and a concentric opening 129' is adapted to fit over the elongated ternnnal 126 with the vertical extension 127 protruding through the opening 12*). The lugs 129 will extend along side the elongated terminal 126 as viewed in Fig. 1. A nut 130 is threadable upon the extension 127 onto a terminal 126. The terminal 126 is provided with a horizontally extending bore 131 extending therethrough and whichihas communication with a bore 132 formed through the circular base 126'. An exposed wire 133 of the ground conductor 134 is inserted into the bore 131 and when the cap 128 is positioned on the terminal 126 and the lugs 129 are in engagement with the sides of the terminal .126, they will engage and clamp the wire to the terminal.

Into the bore 132 is adapted to be threaded a vdiscshaped contact plate 135.

Under either .of the forms of construction shown, the sleeve member is rotatably carried by the block so as to threadably position the terminal together with its ground contact-plate into and out of engagement with the ground of any size or shape.

While I have illustrated and described the preferred form of construction for carrying my invention into effect, this is capable of variation and modification without departing from the spirit of the invention. 1, therefore, do not wish .to :be limited to the precise details of construction set forth, but desire to avail myself of such variations and modifications as of the appended claims.

Having thus described my invention, whatl claim as new and desire to protect by Letters Patent is:

1. A welding ground clamp, a magnetized block for removable attachment to a ground piece, an arm extending longitudinally of said block and insulated therefrom, a circular bearing provided at one end of said arm in spaced relation to one end ofrsaid block, a hollow sleeve carried by said bearing, -means cooperating with said sleeve and operable on said hearing to rotatably connect said sleeve to said bearing, a ground terminal having threadable connection to said sleeve and threadably adcome within the scope 4 justable through a vertical plane with respect thereto when said sleeve is rotated relative to said bearing, said ground terminal provided with a bore through which is inserted one end of a ground conductor and a screw threaded into said ground terminal for releasably fastening said conductor to said terminal, and a replaceable ground plate carried by said terminal and having connection with said conductor to ground the same when said terminal is adjusted into ground contact position.

'2. A Welding ground clamp, a magnetized block for removable attachment to a ground piece, an arm extending longitudinally of said block and insulated therefrom, a circular bearing provided at one end of said arm in spaced relation to one end of said block, a hollow sleeve carried by said bearing, a split ring spring cooperating with saidsleeve and operable on said bearing to rotatably connect said sleeve to said bearing, a ground terminal having threadable connection to said sleeve and threadably adjustable through a vertical plane with respect thereto when saidsleeve is rotated relative to said bearing, said ground terminal provided with a :bore through whichis inserted one end of a ground conductor and a screw threaded into said terminal for releasably fastening said conductor to said terminal, and a replaceable ground plate carried by said terminal and having connection with said conductor to ground the same when said terminal is adjusted into ground contact position.

Blind Nov. '29, 1949 v 

